Radiant gas heater



J. B. SLATTERY RADIANT GAS HEATER May s, 1928.

Filed Sept. 17. 1926 2 Sheets-Sheet 1 INVENTOR. B, 9

A TTORNE Y.

Patented May 8, 1928.

unis B. SLATTERY, or BROOKLYN, NEW YORK.

RADIANT ens HEATER.

Application filed September 17,1926. Serial no. 120,122.

ments from the mantle Without the danger of same fillin the gas outlets and impairing the efficacy of the burner.

These and other objects and details of the invention are more fully described in the I following specification, set forth in the appended claims and illustrated in the accompanying drawings, wherein: p

Fig. 1 is a front View of a radiant heater with burner and its mantles.

Fig. 2 is a vertical sectional view through the same.

Fig. 3 is a fragmentary side view of the burner detached from the base.

Fig. 4 is a similar plan view of the base 2 and the burner.

Figs. 5, 6 and 7 are cross sectlonal views of the burner showing'the flames of various gases.

Figs. 8, 9 andlO showthe actions of burners heretofore used with the same gases.

4 The device shown is part of the ordinary gas heater and consists of a base 12 adapted to be located in. the bottom of the stove and may be secured in any desired manner. It has on its under side depending lugs 13 with a perforation for the bolt 14while on its upper face are ridges 15 and 16 that form an enclosure into which the fire clay mantles 17 are lodged, being several units that are built up into a compact structure shown in Fig. 1.

Through the base 12 from side to side is an elongated opening 18 best shown in Figs.

2 and 4 and to the lugs 13 by means of the bolts 14 the burner is suspended from the base and within the opening so as to deliver the gas jets into the lower end of the perforated fire clay mantles 17.

' The burner consists of the cylinder 19 preferably of sheet metal and having the perforations 20 for the bolts 14. After forming substantially a cylinder the endsof the sheet metal are brought into parallel rela tion forming lips 22, having spaced bays 23,,

and enclosed within the lips is a spacing bar or strip 24.- impinged at intervals by the lips at each side, but theibays 23 leave the bar exposed at oppositesides and form outlets for the gas which when lighted, constitute ets at intervals along the burner; divided by bar 14, thus affording access for the airat all four sides of eachdivided jet to sup ply same with necessary oxygen.

The width of the bar 24 and the distances apart of the bays and jets is sufiieient to admit of the necessary air on all sides of each jet to afford perfect combustion of the gas and prevent the giving off of noxious residues that have been heretofore so objectionable in similar burners.

The size of the bays 23 and their openings is identical on each side of the bar 24 so that the volume of gas issuing from therein is the same and the flames resulting are of equal size and heat.

The ends of the cylinder 19 also have upward extensions 25 fitted against the lips and the bar or strip 24 at their ends and serve to protect them from rough treatment.

In the groups of views, Figs. 5, 6 and 7 and Figs. 8, 9 and 10 for gasesof corres ond ing grade are shown the two types of urners using manufactured gas. Figs. 6 and 9 show the result of a mixed gas while Figs. 7 and 10 show the result in the use of natural gas in the improved and the old burners.

The heretofore use of radiant or mantle heaters has been the subject of much adverse criticism by experts of the United States Bureau of Standards, the United States Bureau of Mines, the AmerieanGas Association, local boards, gas companies and the public.

The reason for this prejudice is that there are, several thousand public utility companics supplying gas with a wide variation in heating values, specific gravity, pressure and chemical composition.

Formerly a manufacturer could provide two'n'iant-le heaters, one for natural gas and one for madegas but the diminishing supply of natural gas has resulted in a mixed gas, part natural and part manufactured, the proportions of which are not constant because the supply of natural gas is limited, and. the greater the demand, the greater the proportion of manufactured gas, so that this mixture varies at short intervals.

Also with manufactured gas there are mixtures of coal gas, water gas and coke oven gas, all of which differ in heating value,

specific gravity and chemical composition.

Radiant or mantle heaters are extremely sensitive to such changes and while it is a comparatively simple matter to construct a mantle heater for agas of constant quality, to construct one that can be supplied to the public at large is an exceedingly diflicult matter.

Radiant or mantle heaters are gene ally constructed as shown in the drawings and are made up of a plurality of refractory mantles each of which, co-acting with Bunsen flames produced by a gas burner of the necessary type are made incandescent and radiate intense heat rays in to the room which is to be heated. These mantles are standardized and of definite size and volume, requiring approximately 1800 British thermal units per hour, each, to maintain their incandescence. The problem then resolves itself into the construction of a mantle heater requiring 1800 B. t. u. per hour for each mantle irrespective of the kind or quality of the gas used.

It is a well established fact that if the gas is not completely burned inside of the mantle, carbon monoxide and other noxious gases escape from the heater, and the escape of these poisonous gases is the reason for the adverse criticism of mantle heaters referred to above. These gases are the result of incomplete combustion and are explained as follows:

The cause of the liberation of carbon monoxide and other noxious gases from a mantle is interference with the sharp blue inner cone of the Bunsen flame in which the first stage of oxidization of the carbon is taking place. This interference may occur in three ways.

First: An insufficient amount of second ary air being admitted inside the mantle which causes the inner cone thatshould be a sharp blue cone to become elongated and merge with the outer cone forming what' is known as floating flames. These flames float outside the mantle seeking air for combustion and a portion is chilled below the combustion temperature and the carbon monoxide and other noxious gases escape unburned.

Second: An insufficient amount of primary air being admitted to the Bunsen flame, which causes an elongated sluggish blue cone producing such a low flame temperature that portions of the outer cone are chilled within the mantle, permitting the noxious gases to escape with the other prodnets of combustion.

Third: The contact of the inner blue cone of the Bunsen flame with the mantle. This arrests the combustion at the point of contact and a portion of the noxious gases escape unburned.

Fourth: When the construction provides more than one inner cone for each mantle,

the merging together of these inner Comes to form one elongated sluggish blue flames which allow the noxious gases to escape both as explained above. under the first, second and third headings.

Fifth: The corrosion or oxidization of the burner slots. This clogs up the slots and entirely destroys the eliiciency of the burner design, causing the heater to give off carbon monoxide and other noxious gases in profuse and deadly quantities.

The flame chaacteristics of a Bunsen flame delivering the same quantity of heat (in this case 1800 B. t. u.) varies greatly according to the chemical composition and the specific gravity of the gas used. It is impractical to use a single port Bunsen burner for radiant heaters in the United States as their use requires a fixed quality of gas and specific gravity. Under this ideal condition, the generation of carbon monoxide is such that good chimneycom nections are necessary. Both of these conditions are found in England, where the single port burner is used extensively. To overcome the objection to the single port burner, the slotted burner was designed such as shown in Figs. 8, 9 and 10.

The burner therein shown has for its principle that if gas issues through a number of small slots at a high velocity and with a high primary air injection a distinct Bunsen type flame is produced at each slot. Experience and use have shown that such burners are very sensitive to changes in gas quality and specific gravity. Formerly when two gases only (manufactured and natural) of fairly uniform quality and specific gravity were used throughout the country, this burner was made in two designs, one for natural and one for manufactured gas. With the advent of mixed gases and various grades of manufactured gas, these burners failed to function properly, hence the agitation against the use of radiant heaters by the agencies above mentioned.

The reason for their failure can be read ily seen by referring to'Figs. 8, 9 and 10 where with the same heat output, the size of the flame varies according to the gas used. A burner designed for use of manufactured gas, Fig. 8, if used with mixed gas,

Fig. 9, would not give separate distinct Bunsen flames at each slot, but would merge together as one lazy Bunsen flame and such a flame requires a large amount of secondary air, which this burner doesnot permit of, consequently the envelope flame reaches out for air,through the mantle bpft is chilled and carbon monoxide is given 0 When used for natural gas, Fig. 10, the situation is even worse, as the blue cone itself comes in contact with the mantle and is chilled below the combustion temperature so that large quantities of poisonous gases are given ofl. This merging is due to the difference in size of the flames when various gases are used.

Another defect in the multiple slot burner is that use has shown that the blue cones do not burn on the surface but back in the slot to an appreciable distance so that the metal strips are heated to such a high temperature that corrosion or oxidization takes place. To overcome this, chrome nickel steel or other high priced material must be used to oflset this destructive action.

The present invention was designed with a thorough knowledge of the weakness of the multiple slot burners as originally made and but two slots were employed for the followmg reasons:

First: So that an ample supply of secondary air could reach at least one side of each Bunsen flame and thus assure an air supply for complete combustion.

Second: Two slots could be separated by a strip of sufficient width to prevent the merging of the blue cones when operated on different gases which give various size flames for the same B. t. 11. output.

Third: The use of two slots with a comparatively wide dividing strip, when placed within the confined and limited space provided by the radiant mantle, still allows the blue cones to vary in size when used with different gases; so under no conditions of quality or specific gravity of the gas will the blue cones, which remain under all conditions separate and distinct, impinge on any part of the mantle that would cause carbon monoxide to escape from the heater.

Fourth: The accessibility of the two Bunsen flames to a supply of secondary air make the high primary air injection unnecessary consequently the blue cones do not back down in the slots, resulting in high temperature with consequent corrosion or oxidization when expensive high temperature resisting metals are not used.

It is evident, therefore, that this improved burner is constructed on scientific lines after long experiments and actual use by parties thoroughly expert in the use of gas for heating purposes and that the freedom of the divided flame provides all the air necessary for the proper functioning of the burner and the complete combustion of the gas.

essential features above described or from p the scope of the appended claims.

What I claim as new is:

1. In radiant gas heaters, the combination of a hollow body portion having two generally parallel flanges forming a channel in communication with the body portion, alternate sections of the said channel being of difl'erent widths, a bar of substantial thickness entirely closing the narrow sections of said channel and dividing the wider sections into two longitudinal outlets, and a radiant supporting base having an oblong aperture of substantially greater width than the said channel and into which the said channels protrude whereby air is fed to all sides of each gas outlet.

2. In radiant gas heaters, the combination of a hollow cylindrical body portion having upwardly extending substantially parallel flanges to form a channel in communication with the body portion, alternate opposite sections of said channel being of difierent widths, a bar of substantial thickness fitting.

between and entirely closing the narrow sections of the said channel and dividing the wider sections into two opposite longitudinal outlets, and a radiant supporting base having an oblong aperture of substantially greater width than said channel and into which they protrude to admit air to all sides of each gas outlet.

3. In radiant gas heaters, the combination of a hollow sheet iron body section whose ends are formed into substantially parallel flanges to form a channel communicating with the body section, said flanges being formed. with alternate sections of diflerent distances apart and the corresponding sections being opposite each other, a bar of substantial thickness entirely closing the sections of lesser width and dividing the space between the sections of greater width into two opposite longitudinal outlets, and a radiant supporting base having an oblong aperture to receive the said channel and permit the entrance of air to all sides of each gas outlet.

In testimony whereof I hereunto aflix my signature.

JAMES B. SLAT'IERY. 

